Income Taxes - Net Deferred Tax Position (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for credit losses	$ 153	$ 131
Interests in real estate mortgage investment conduits	181	182
Unrealized losses on investment securities	36	164
Capitalized costs	595	680
Fair value adjustments	15	0
Other	364	350
Total deferred tax assets	1,344	1,507
Valuation allowance	(8)	(6)
Total deferred tax assets, net of valuation allowance	1,336	1,501
Deferred tax liabilities:
Fair value adjustments	0	75
Amortization of intangible assets	18	18
Other	18	22
Total deferred tax liabilities	36	115
Net deferred tax asset	$ 1,300	$ 1,386